Ribbon feeding and reversing mechanism for printing machines



May 8, 1956 J D. GEARHEART ET AL 2,744,605

RIBBON FEEDING AND REVERSING MECHANISM FOR PRINTING MACHINES Filed May 28,- 1953 4 Sheets-Sheet 2 INVENTOR),

JofinD. ear/zeari'& BY Mmon \(Jcozzafava X/ZW HTTORNEX y 3, 1956 J. D. GEARHEART ETAL 2,744,605

RIBBON FEEDING AND REVERSING MECHANISM FOR PRINTING MACHINES Filed May 28, 1953 4 Sheets-Sheet 5 am fih w. Yn d R 82 0 0 0 T TF T H WU V" n T JMH/m y 1956 J. D. GEARHEART' ETAL 2,744,605

RIBBON FEEDING AND REVERSING MECHANISM FOR PRINTING MACHINES Filed May 28, 1953 4 Sheets-Sheet 4 HTTORNEX United States Patent RIBBON FEEDING AND REVERSING NIECHANISM FOR PRINTING MACHINES John D. Gearheart, Baldwin Park, and Milton V. Scozzafava, Temple City, Calif., assignors to Clary Corporation, a corporation of California Application May 28, 1953, Serial No. 357,992

6 Claims. (Cl. 197-165) This invention relates to printing ribbon mechanism used in conjunction with printing adding machines, cash registers, calculators, typewriters, etc., and has particular reference to feeding and reversing mechanisms for printing ribbons.

Provision is made in certain of the above and other types of business machines to print characters on two or more superimposed strips or pieces of paper from a single ribbon and from a common set of type by guiding the ribbon in strands back and forth across the paper. The strands are separated slightly to permit the paper strip to be passed therebetween to thus obtain multiple printing.

Although arrangements of the foregoing type have generally proved satisfactory, any tendency for the ribbon to sag not only causes smudging due to rubbing of the paper over the ribbon as the former is advanced, but such sagging also renders threading of the paper strips between the ribbon strands diflicult. Also, such sagging of the ribbon strands might allow the ribbon to catch on adjoining parts.

Heretofore, friction clutches have generally been applied to the ribbon supply roll to retain the ribbon in a taut condition. This expedient, however, adds to the load imposed on the ribbon feeding mechanism, especially when the latter is guided over and around a number of guiding elements in order to define a desired ribbon path. As the speed of the machine is increased, the increase in loading tends to cause misoperation of the ribbon feeding and reversing mechanism.

Therefore, the principal object of the present invention is to provide a ribbon feeding mechanism which will retain the ribbon in a substantially taut condition during printing operations and yet which will not impose a load during ribbon feeding operations.

Another object is to provide a simple, compact ribbon feeding and reversing mechanism.

. Another object is to provide a ribbon feed mechanism which is not critical of adjustment or manufacturing accuracy.

Although the invention is particularly applicable to mechanism for feeding ribbon through a folded back or sinuous path in order to obtain duplicate printed copies,

at least the broad aspects of the invention are equally applicable to ribbon feeding mechanisms where only a single ribbon strand is used to obtain a single printed copy. The manner in which the above and other objects of the invention are accomplished will be readily understood on reference to the following specification when read in conjunction with the accompanying drawings wherein:

Fig. 1 is a fragmentary plan view of a cash register machine embodying the invention.

Fig. 2 is a plan view of the ribbon feedingdevice with the cover of Fig. 1 removed.

Fig. 4 is a sectional plan view taken on line 4-4 of Fig. 3 and Fig. 8.

Fig. 5 is a sectional elevational view taken on the line 5-5 of Fig. 2. I

Fig. 6 is a vertical sectional view on line 6-6 of Fig. 3 and Fig. 8 on an enlarged scale.

Fig. 7 is a sectional view on line 7--7 of Fig. 6 on the smaller scale. A

Fig. 8 is an enlarged view of a portion of Fig. 3.

Fig. 9 is a sectional elevational view through the upper portion of the device showing its relation to the machine cover and is taken on line 99 of Fig. 1.

Fig. 10 is a sectional View similar to Fig. 9 but taken on line 10-10 of Fig. 1.

Fig. -11 is a sectional view similar to Fig. 10 but taken on line 11-11 of Fig. 1.

Although the disclosed invention may be usefully employed as a ribbon feed in other types of machines, it is shown to be applied to a cash register of the type disclosed and claimed in the patent to Boyden et al. 2,607,526, issued on August 19, 1952. Mechanism comprising the register is disclosed and claimed in the Boyden Patent No. 2,583,810, issued on January 29, 1952, and the Drake Patent No. 2,472,696, issued on June 7, 1949. Therefore, only those parts of the cash register which intimately relate to and coact with the parts embodying Fig. 3 is a sectional elevational view taken on line 3-3 of Fig. 2.

the present invention will be disclosed herein, and reference may be had to the aforesaid patents for an understanding of the complete machine.

The ribbon feed mechanism is driven by a rotatable drive shaft 12 (Fig. 3) which rotates one complete revolution during each cycle of the machine. The shaft 12 carries a cam 13 engaging a roller 14 carried by a lever 15 pivoted on a fixed shaft 16 and urged counterclockwise by a tension spring 11. A link 17 provides a connection between the lever 15 and a slide plate 18 supported for vertical reciprocation by slots 19 and 20 embracing, respectively, a frame pin 21 and a pin 22, the latter carried by a bracket 23 suitably attached to a printer frame 24.

The pin 21 is also embraced by a slot 25 provided in a double tongued pawl member 26 designed to be moved downwardly by a latch 27 pivoted on a pin 28 fixed in the lower end of the plate slide 18. The latch 27 is urged toward engagement with a lug 29 provided on a depending leg 30 of the pawl 26-by a spring 31. Another depending leg 32 of the pawl26 is separated from the leg 30 so as to form a slot 33 wherein the pin 28 is slidably movable.

A spring 34 connected at one end to a lug 35 formed on the lower end of the leg 30 and at its other end to the pin 21 urges the pawl 26 upwardly so as to move tongues 36 and 37 of the latter into engagement, respectively, with ratchets 38 and 39 journalled on pins 40 and 41 fixed in a frame extension 42. A pair of pinions 43 and 44, also journalled on the pins 40 and 41, are fixed to the ratchets 38 and 39, respectively.

A pair of gears 45 and 46 journalled on frame pins 47 and 48 are driven respectively by the pinions 43 and 44 and are connected, as by pins 49 and 50, to ribbon spools 51 and 52, respectively (Fig. 5).

An ink impregnated ribbon 54 has one of its ends attached to the hub of the spool 51 and the other of its ends attached to the spool 52 and, in between its ends, is

threaded through and over various ribbon supporting and Patented May: 8, 6

rearmost ribbon strand, and the other extending between the two strands.

The rollers 55 are journalled on frame pins 62, and the plates 56 and 57 are, riveted at 63 toframe brackets 64 and 65, respectively. The guide 53 is'also riveted at 66 to the bracket 64, and the guide 59 is secured as by screws 67 to another part of the printer frame 24.

The bell cranks 60 and 61 each consist of two parts pivoted upon one of a pair of frame pins 68. These parts normally move as one by reason of a spring 69. The latter is tensioned between such two parts to normally hold a lug 69a on one against an engaging edge of the other. a

The upper ends of the bell cranks 60and 61 are each bifurcated so as to form slots 70 and 71, respectively, through which the ribbon 54 passes. The lower ends of the bell cranks are respectively provided with pins 72 and 73 engaging slots 74.and 75, respectively, in a reversing bar 76 slidably supported on frame pins 77 and 78.

The bar 76 has a pin and slot connection 79 with an oscillatable plate 80 pivoted upon the frame pin '78 and having another pin and slot connection 731 with a stop bar 82. The latter is provided with longitudinally extending slots at opposite ends thereof which slidably embrace the frame pins 21 and 78.

The bar 32. is normally held in a neutral position as illustrated in Figs. 3 and 7 by the bell cranks 60 and 61 which in turn are held in engagement with the rollers 55 by tension springs 130. In this position of the bar 82 an upstanding blocking lug 83 thereonis located intermediate a pair of camming bars 84 and 85. The latter are slidably connected at their upper ends to the plate 18 by pins 86 and 87 fixed in the plate 18 and embraced by slots in the bars. Pins 33 and 39-extend from the lower ends of the bars 84 and S and are guided in slots 90 and 91 provided in the plate 18 to permit independent vertical movement of the bars relative to the plate 18.

A pair of springs 92 and 93 (Fig. 3) connected at their upper ends tothe pins 38 and 89 and at their lower ends to lugs 94 formed on the plate 18, urge the bars 84 and 85 tothe limits of their downward movements where lugs 104 thereon lie slightly above the plane of the upper edge of the blocking lug 83 or" bar 82. A generally U-shaped pawl 95 (Figs. 6, 7 and 8) has one leg pivoted on a pin 96 fixed in the plate 18 and the other leg pivoted on a pin 97 axially aligned with the pin 96 and fixed in an extending arm 98 of the plate 18. The pawl 95 is connected by an overcenter tension spring 99 to a generally heart-shaped cam plate 100 also pivoted on the pin 96. The points of attachment of the spring 99 to the pawl 95 and plate 100 lie on diametrically opposite sides of the pivot pin 96 so as to yieldably maintain those elements, alternatively, mainly to the right of the pin 96 as shown in Fig. 8 or to the left thereof.

The bars 84 and 85 are provided with pins 101 and 102, respectively, adapted to underlie one or the other lobe of the cam plate 100, depending on the rocked position of the latter.

in Fig. 5, the spools 51 and 52 are shown ashaving been rotated clockwise until the spool 52 is nearly full and the spool 51 is nearly depleted of ribbon.

Further rotation of the spool 52 would draw the ribbon 54 until an eyelet 103, attached to the ribbon near its end. engages the bell crank 60, causing the bell crank to rock and thus move the bar 76 toward the left (Fig. 3), rocking the plate 8.0 counterclockwise, thereby moving the bar 82 toward the right until the stop lug 83 rests beneath a foot 104 of the bar 85.

During the next machine cycle the link 17 will pull the plate 13 downwardly. Normally, when the stop lug 83 is in the central or neutral position, the bars 84 and 85 follow the bar 18 downwardly due to the pull of the springs 92 and 93, but now.that the stop lug 83 rests beneath the foot 104, the bar,85 is prevented from lowering and the pin 102 fixed in the bar is engaged by the cam plate 100, thereby carnming the latter counterclockwise (Fig. 8) due to the lowering of the pivot pin 96 with the plate 18. The upper end of the spring 99 is thus moved to the left past the center of the pin 96, thereby snapping the lower .endof the pawl toward the left to a position over the teeth of the ratchet 38. Thereafter, further cycling of the machine will cause reciprocation of the pawl 95 to rotate the ratchet 38, thereby rotating the spool 51 counterclockwise to rewind the ribbon thereon until a second eyelet 106 near the other end of the ribbon 54 contacts the bell crank 61. The latter bell crank will then reversely shift the bar 76 and associated parts. For this reversal, the pin 101 functions in a manner similar to the pin 102 to rock the cam plate back to its position illustrated in Fig. 8.

Each time the plate 18 is lowered, the pin 28 at the lower end thereof will, through the latch 27 and the lug 29, lower the pawl 26 away from the ratchets 38 and 39 so that pawl 95 will be free to rotate either ratchet, depending on its rocked position. Just prior to the completion of the downward stroke of the pawl 95 an arm 108 of the latch 27 will engage a frame pin 109, thereby rotating the latch clockwise away from the lug 29 to release the pawl 26, permitting the spring 34 to return the pawl upwardly into locking engagement with both ratchets. Thus, both spools will be locked against rotation and the ribbon will be held substantially taut until advanced by the next stroke of the pawl 95.

The relationship between the pawl 95 and the pawl 26 is such that the pawl 95 will commerce to drive one of the ratchets just prior to release of the pawl 26 from both ratchets. Therefore, in the event any tensions have been created in the slightly flexible ink ribbon, due to the speed of operation of the mechanism, retrograde rotation of the take-up spool will be prevented.

Ticket validating In addition to their function as supports for guiding the ribbon along the face of the platen to print on a paper tape extending over such platen, the guides 58 and 59 provide part of the means for locating a ticket or slip (indicated by dotted lines 110) in a position to be printed.

The guide 58 is aligned with a slot 111 and the guide 59 is aligned with a slot 112, both slots being formed through the top of a machine cover 113 and aligned laterally with each other on opposite sides of a central opening 131 through which the paper tape 110 extends. The slot 111 is continued through one side of the cover as shown in Fig. 10 to permit the ticket tobe slid along the aligned slots 111 and 112, laterally of the machine.

In order to guide the ticket or slip into the slots 111 and 112, humped members 114, 115 and 116 are mounted on the top of the cover 113. These members are secured to the cover on opposite sides of the slots 111 and 1.12 by bent over tabs 117 which extend through apertures in the cover, similar to aperture 118.

As shown, particularly in Fig. 10, the slots 111 and 112 are located directly over the guides 58 and 59, so that the ticket to be validated may be easily slipped between the two strands of ribbon.

The printer includes means (not shown) for rotating the platen 119 andthus feeding a pair of-paper tapes, indicated by dotted lines 122 and 123, thereover so as to obtain duplicate records of amounts registered by the machine. For this purpose, a trough 121 (Fig. 9) is provided, being pivoted on a frame pin 133 and urged toward the platen by suitable springs (not shown). The trough terminates in a pair of spaced upwardly extending guide fingers 134 (see also Fig. 2) arranged toguide the tape directly behind the rearmost strand of the ribbon 54.

A second trough 135 is pivotally supported on a frame pin 136 and rotatably supports a pressure roller 137. A spring 138 connected between the lower end of the trough 135 and a frame pin urges the latter toward the platen to cause the pressure roller 137 to press both tapes against the surface of the platen. Spring fingers 140 on the upper end of the trough 135 guide the outer tape 122 adjacent the rear strand of the ribbon and provide a space for inserting the ticket 110.

Having thus described the invention, what we desire to secure by United States Letters Patent is:

1. A printing ribbon feeding mechanism comprising the combination of a pair of spools for feeding a printing ribbon therebetween, a ratchet wheel, means operatively connecting said ratchet wheel to one of said spools, actuating means for incrementally actuating said ratchet wheel, a retaining pawl normally engaging said ratchet wheel, means operable by said actuating means during actuation of said ratchet wheel for disengaging said pawl, and means for causing re-engagement of said pawl before completion of actuation of said ratchet wheel.

2. A printing ribbon feeding and reversing mechanism comprising the combination of a pair of spools for feeding a printing ribbon therebetween, a first ratchet wheel, means operatively connecting said ratchet wheel to one of said spools, a second ratchet wheel, means operatively connecting said second ratchet wheel to the other of said spools, a retaining pawl device normally engaging both of said ratchet wheels, actuating means for alternately and incrementally actuating said ratchet wheels, means operable by said last-mentioned means for disengaging said pawl device during actuation of one of said ratchet wheels, and means for causing re-engagement of said pawl device before completion of actuation of one of said ratchet wheels by said actuating means.

3. A printing ribbon feeding and reversing mechanism comprising the combination of a pair of spools for feeding a printing ribbon therebetween, a first ratchet wheel, means operatively connecting said ratchet wheel to one of said spools, a second ratchet wheel, means operatively connecting said second ratchet wheel to the other of said spools, retaining pawls for said ratchet wheels, spring means for urging said pawls into engagement with said ratchet wheels, actuating means for alternately and incrementally actuating said ratchet wheels, said actuating means being reciprocable through advancing and return strokes, means comprising a disconnectable coupling operable by said actuating means during an advancing stroke thereof for disengaging said retaining pawls, and means responsive to movement of said actuating means during said advancing stroke thereof for releasing said coupling.

4. A printing ribbon feeding and reversing mechanism comprising the combination of a pair of spools for feeding a printing ribbon therebetween, a first ratchet wheel, means operatively connecting said ratchet wheel to one of said spools, a second ratchet wheel, means operatively connecting said second ratchet wheel to the other of said spools, a reciprocable actuator slide, an actuator pawl pivotally carried by said actuator slide, a camrning element pivotally carried by said slide, an overcenter spring extending between said camrning element and said pawl and adapted upon rocking movement of said camrning element from one position to another to rock said pawl from engagement with one of said ratchet wheels to engagement with the other, a pair of reciprocable control slides carried by said actuator slide and each adapted upon relative movement between the same and said actuator slide to cam said camrning element from one of said positions to the other, and stop means for selectively and alternately arresting one or the other of said control slides.

5. A printing ribbon feeding and reversing mechanism according to claim 4 comprising a retaining pawl device normally engaging both of said ratchet wheels, means comprising a disconnectable coupling operable by said actuator slide during actuation of one of said ratchet wheels by said actuator pawl for disengaging said retaining pawl device from said ratchet wheels, and means engageable by said coupling device during actuating movement of said actuator pawl for causing re-engagement of said retaining pawl device.

6. A printing ribbon feeding mechanism comprising the combination of a supply spool for a printing ribbon, a take-up spool for said ribbon, a first ratchet wheel, means operatively connecting said first ratchet wheel to said. supply spool, a second ratchet wheel, means operatively connecting said second ratchet wheel to said take-up spool, a retaining pawl for said first ratchet wheel, spring means normally maintaining said retaining pawl in en- 1 gagement with said first ratchet wheel, an actuating pawl for incrementally actuating said second ratchet wheel, reciprocable means for operating said actuating pawl through actuating and return strokes, means comprising a disconnectable coupling operable by said reciprocable means for disengaging said retaining pawl, and means operable during said actuating stroke of said actuating pawl for disconnecting said coupling.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Feb. 6, 1952 

